Tumor cytotoxic factor, hereinafter abbreviated as TCF, is an another name of TCF-II found in a cultured supernatant of human fibroblast cells and disclosed in WO 90/10651. TCF is a glycoprotein consisting of heterodimer having molecular weight of about 76-80 kDa in unreduced state, and .alpha. subunit having molecular weight of about 52-56 kDa and .beta. or .beta.' subunit having molecular weight of about 30-36 kDa in reduced state.
TCF exhibits various biological activities such as the activities of hepatocyte growth factor; HCF, scatter factor; SF, proliferation factor of renal tubular epithelial cells, repair factor for damaged tissues and proliferation factor of vascular endothelial cells. In addition to TCF activity. TCF is a cytokine belonging to a member of HCF family. TCF is expected to be developed as pharmaceuticals for the treatment of diseases of liver and kidneys, wounds and tumors due to its various kinds of physiological activity.
However, the solubility in water of TCF is very low. Thus aqueous preparations such as injections with high concentrations satisfying medical use are hardly obtained. Therefore, one of the most serious subject to be solved for its application to the clinical use is preparing such a concentrated solution of TCF. TCF has rapid metabolic turnover in vivo and high dosage is expected on the clinical use. The clinical dosage of TCF is expected to be 1 10 mg/day for adult patients. To make sure of the quality of final products, such as injections, the production processes require to dissolve TCF at high concentrations and to mix it with additives such as stabilizers under low temperatures. Furthermore, a highly concentrated TCF solution is demanded for medical treatment, that is the solution of neutral pH and has isotonicity for injections. No such method to prepare highly concentrated TCF solution has been developed yet. For example, an isotonic saline solution, containing 0.15M sodium chloride usually used for injections, dissolves TCF less than 5 mg/ml and the TCF solution is unstable. The solubility of TCF decreases and TCF becomes insoluble with the progress of time at room temperature. Furthermore, solubility of TCF in saline markedly decreases to about 1 mg/ml at 5.degree. C. or lower.
Therefore, it is an important subject to establish a method for preparing a neutral, isotonic and highly concentrated TCF solution at low temperatures. Above mentioned WO 90/10651 discloses preparations containing a protein, a sugar, an amino acid and so forth as an adsorption preventive agent or a stabilizer. However, neither highly concentrated TCF solution of the present invention is disclosed nor suggested.
Thus, the object of the present invention is to provide a highly concentrated and isotonic TCF injection solutions for medical treatment.